Over the past 50 years, there has been a fundamental shift in population dynamics in Asia. Fueled by economic growth and the diffusion of new ideas and health and family planning technologies, both mortality and fertility have declined in every country of the region. Between 1950 and 2000, life expectancy in East Asia rose from 43 to 72 years, and fertility dropped from more than five to less than two children per woman. The countries of Southeast and South and Central Asia have begun the transition to low mortality and fertility, but most are not as far advanced. Yet even in the less developed countries of the region, death and birth rates have fallen, and population growth rates and structures are changing. This demographic transition has provided favorable conditions for accelerated social and economic development.